Have you run into this problem?

Many of you have alerted me to the problem with lines getting cut off in the forums and elsewhere. This problem started around the time of the upgrade, and while it had happened before, it seemed to be related.

Well, it's now been diagnosed with a 95% certainty: it seems that ads from a particular vendor are causing this problem. Take a look at the banner ad at the top of both screenshots:

So this issue has been sent up to the online ad folk at the Denver Newspaper Agency. When it gets fixed I'll post the results here.